Quantification of Induction Motor Bearing Fault based on Modified Winding Function Method

This paper investigates the analysis and modeling of an induction motor with ball bearing faults based on coupled-circuit model and modified winding function method (MWFM). The impact of the bearing fault is reflected in the variation of air gap profile, and the inductances terms in the coupled-circuit model are calculated and updated for each time step using MWFM. We show that dynamic simulation of an induction motor with bearing fault can be performed with the model, and the stator current spectrum can be calculated to identify the corresponding fault signatures. The method helps quantify bearing fault severity level by monitoring the amplitude of corresponding faulty current components, which facilitates condition-based monitoring of electric machines using motor current signature analysis (MCSA).